The Hong Kong central bank and its exchange have also begun an assessment of the impact if Britain votes to leave the European Union (EU) in the June 23 referendum.

Some Asian asset managers are looking to set up new bases in mainland Europe amid growing concerns their operations could be disrupted if Britain votes to leave the EU, reported Reuters.

"Singapore's banking system remains sound and resilient, with strong capital and liquidity buffers to withstand shocks," an MAS spokesman said.

"Nonetheless, the current uncertain external environment underscores the importance of staying vigilant to new or growing risks and vulnerabilities".

A spokesman for the Hong Kong Monetary Authority also warned of "significant uncertainties" in the event of an "Out" vote.

The contingency planning highlights concerns that Brexit, as Britain leaving the EU has been called, could have ripple effects in the Asia-Pacific by cutting off the UK's Asian finance investors from the EU financial market. Other regions are also making Brexit preparations.

Opinion polls have pointed to a close vote, though the most recent polls show rising support for Britain staying in the EU.

"A potential Brexit is an issue no organisation can afford to ignore," a spokesman for Hong Kong Exchanges and Clearing, which took over the London Metal Exchange (LME) and its clearing house in 2012, told Reuters.

"We are carrying out an impact assessment for both the LME and LME Clear and are addressing the short-, medium- and long-term implications for both potential outcomes of the UK referendum."

The bourse declined to elaborate on its impact assessment, though risk management experts said it would likely cover the legal, regulatory and operational implications of Brexit, as well as volatility scenarios and potential market disruptions.

Asian investors using Britain as their European base said they may establish operational bases in Germany or Luxembourg, fearing an "Out" vote would disrupt their ability to offer services and products across the 28-nation EU.

"There's lots of uncertainty. If the vote is "Out" would London be a platform for accessing Europe?" asked Ms Sammi Shen, executive director at Shanghai Nord Engine Asset Management Group, a US$3 billion (S$4 billion) Chinese investment management company which set up a London office only last year.

"We would find a European partner or set up an office in Europe - that's our back-up plan," she said, listing Germany and Luxembourg as the preferred locations.

This article was first published on April 23, 2016. Get a copy of The Straits Times or go to straitstimes.com for more stories.